Japanese Kokai SHO 54[1979]-79214 discloses a process for the catalytic synthesis of 2-butene-1,4-diol from a starting material of 3,4-epoxy-1-butene. If the reaction is carried out using only hydriodic acid as a catalyst, the desired reaction product is disclosed to be obtained with selectivity up to about 57%, but with yields in the range of only about 15%-25%. It is suggested that if a transition metal compound is employed in combination with hydriodic acid as a catalyst, the selectivity of the reaction is improved. The term "transition metal compound" is defined as encompassing compounds consisting of group IIIA, IVA, VA, VIA, VIIA, VIII, and IB elements of the fourth, fifth, and sixth period of elements in the periodic table of elements. More specifically, compounds containing ytrrium, lanthanoid elements, titanium, zirconium, vanadium, molybdenum, tungsten, manganese, rhenium, iron, ruthenium, osmium, cobalt, rhodium, iridium, nickel, palladium, platinum, copper, silver, and gold can be employed. The highest yield reported is 57% employing a combination of hydroiodic acid and manganese dioxide. All other reported yields are below 50%.
Japanese Kokai SHO 50[1975]-88514 discloses a non-catalytic process for the preparation of a 4-alkylcarbonyloxy 2-buten-1-ol by first reacting 3,4-epoxy-1-butene with potassium iodide to produce 4-hydroxy-3-iodo-1-butene, followed by reaction with acetic acid.
Tsuji, Kataoka, and Kobayashi, "Regio-selective 1,4-Addition of Nucleophiles to 1,3-Diene Monoepoxides Catalyzed by Palladium Complex", Tetrahedron Letters, Vol. 22, No. 27, pp. 2575-2578, 1981, discloses the reaction of 1,3-diene monoepoxides in the presence of Pd(PPH.sub.3).sub.4 with compounds such as dimethylmalonate, acetoacetate, pyrrolidine, 2-methyl-1,3-pentanedione, and allylsulfonyltoluene. In no instances is the formation of a 1,4-dioxy substituted 2-butene taught.
Tsuda, Tokai, Ishida, and Saegusa, "Palladium-Catalyzed Reaction of 1,3-Diene Monoxides with .beta.-Keto Acids, Allylic Alkylation and Isomerization of 1,3-Diene Monoepoxides", Journal of Organic Chemistry, 1986, Vol. 51, pp. 5216-5221, is, to the extent pertinent, essentially cumulative in its teachings.
Trost, Urch, and Hung, "Regiochemical Directing Effects in Palladium Catalyzed Alkylations with Polyene Electrophilic Partners", Tetrahedron Letters, Vol. 27, No. 41, pp. 4949-4952, discloses the alkylation of complex diene monoxides with carbon nucleophiles in the presence of Pd(PPh.sub.3).sub.4.
Fujinami, Suzuki, Kamiya, Fukuzawa, and Sakai, "Palladium Catalyzed Reaction of Butadiene Monoxide With Carbon Dioxide", Chemistry Letters, pp. 199-200, 1985, discloses the conversion of butadiene monoxide to a 3,4-carbonato-1-butene employing Pd(PPH.sub.3).sub.4 as a catalyst.
Palladium catalyzed reactions involving cyclic and acyclic diene monoxides are also reported by the following:
Trost, Lynch, and Angle, "Asymmetric cis-Hydroxylation via Epoxidation-Carboxylation: A Formal Synthesis of (+)-Citreoviral", Tetrahedron Letters, Vol. 28, No. 4, pp. 375-378.
Trost and Angle, "Palladium-Mediated Vicinal Cleavage of Allyl Epoxides with Retention of Stereochemistry: A Cis Hydroxylation Equivalent", J. Am. Chem. Soc., 1985, Vol. 107, 6123-6124.
Trost and Molander, "Neutral Alkylations via Palladium(0) Catalysis", J. Am. Chem. Soc., 1981, Vol. 103, pp. 5969-5972.
Deardorff, Myles and MacFerrin, "A Palladium-Catalyzed Route to Mono- and Diprotected cis-2-Cyclopentene-1,4-diols", Tetrahedron Letters, Vol. 26, No. 46, pp. 5615-5618 (1985).
Deardorff, Shambayati, Linde and Dunn, "Palladium-Catalyzed Syn, 1,4-Additions of Silyl-Derived Carboxylates and Phenoxides to Cyclopentadiene Monoepoxide. A Stereo- and Regiocontrolled Route to Differentially Protected cis-2-Cyclopentene-1,4-diols", J. Org. Chem., 1988, Vol. 53, pp. 198-191.
As the above-described prior art makes clear, the preparation of 1,4-dioxy substituted 2-butene compounds from 3,4-epoxy-1-butene by catalytic reactions has been generally known prior to the present invention. However, conventional processes have exhibited a variety of disadvantages. For example, many processes, though producing the desired 1,4-dioxy substitution pattern also produce large amounts of undesired 1,2-dioxy isomers.
The highest levels of selectivity in achieving the desired 1,4-dioxy substitution pattern (&lt;60%) have been achieved employing hydriodic acid or alkali metal iodide salts. In either case, a highly corrosive acid reaction medium is created. Refluxing or otherwise heating the reaction medium exacerbates problems of equipment corrosion.